Japan Flora: Dextrorsely twining deciduous shrub loosely short-pubescent but soon glabrous; stipules subulate, persistent, the leaflets 11-17, ovate to narrowly so, 1.5-4 cm. long, 1-2 cm. wide, gradually narrowed to the obtuse apex, rounded at base, slightly paler beneath, rather veiny on both surfaces, nearly glabrous, deep green above; racemes axillary, 10-20 cm. long inclusive of the short peduncle, rather densely many-flowered, nodding; flowers greenish white,pedicelled, about 15 mm. long; calyx about 4 mm. long, loosely appressed-puberulous, the teeth depressed- deltoid, the bracts and bracteoles acicular, less than 1 mm. long, persistent; ovary smooth, glabrous; legumes about 10 cm. appressed-puberulous, the teeth depressed- deltoid, the bracts and bracteoles acicular, less than 1 mm. long, persistent; ovary smooth, glabrous; legumes about 10 cm. long, 8 mm. wide. July-Aug. Thickets in lowlands; Honshu (centr. distr. and westw.), Shikoku, Kyushu; rather common.
cv. Microphylla A non-flowcring cultivar, slightly pilose, with rather densely leafy branches and narrower leaflets than in the typical phase.